The present invention relates to a seat for vehicles, particularly motor vehicles, as well as to an adjusting arrangement thereof.
More particularly, the present invention relates to a vehicle seat and an arrangement thereof which have a plurality of individual adjusting elements arranged to adjust the seat in correspondence with a seat user and a vehicle, wherein a motor acts via a driving pinion onto different driven shafts of a distributing transmission which actuate these adjusting elements.
Seats used in motor vehicles are adjusted with regard to position of the seat user in the vehicle relative to the actuating elements such as steering wheels, pedals, switches, levers, etc., and also for optimum direct and indirect visibility outside, in height, inclination, and longitudinal direction of the seat. Moreover, it is necessary to provide ergonomically correct fatigue-proof sitting of the seat user by adjusting the seat pad and backrest in the sense of the seat inclination, seat width, lateral support, seat profile, etc., relative to the seat user. For this purpose, modern seats and also their head supports are adjustable in several directions. These seat adjustments can be performed both manually and also by a motor in comfortable manner.
For performing several adjusting movements in the seats of vehicles one after the other with only one drive motor, a distributing transmission is provided in which an adjusting unit of such transmission is composed of electromagnets. The electromagnets are formed annular and are fixedly supported in a housing of the distributing transmission. Each electromagnet surrounds a driven shaft in such a manner that axially displaceable and non-rotatable coupling disks can be pressed in the event of a current supply in the respective electromagnet by the latter to a gear which loosely rotates on the driven shaft. In the known distributing transmission, several driven shafts are arranged adjacent to one another so that at least two driven shafts engage with the pinion of the drive motor, whereas the gears of further driven shafts are in engagement with the gears of the first-mentioned driven shaft. Since the gears are loosely rotatably supported on the driven shaft, a torque transmission is performed via the driven shaft whose electromagnet connects the coupling disk with a gear rotating on the drive shaft to be coupled. When there is no current in the respective electromagnet, a pressure spring arranged between the gear and the coupling disk presses the coupling disk from the gear, so that the coupling connection is lifted. The driven shaft of the distributing transmission can be connected with the respective adjusting elements of the seat frame or the backrest via flexible shafts. Switching of the electromagnet associated with the respective driven shaft can be performed for each adjusting element from the same drive motor.
In addition to the electromagnetically actuating distributing transmission, a mechanically adjustable distributing transmission is known. It has an adjusting element actuated by a servo or auxiliary motor and formed as an adjusting spindle, and an adjusting shoe which engages and disengages couplings on the adjusting spindle. The adjusting shoe, which is displaceable over the adjusting spindle, presses by respective displacement on the adjusting spindle onto the adjusting spindle an adjusting lever associated with the respective coupling into engaging position, so that the coupling, which is connected rotation-fixed but axially displaceable with a driven shaft, is pressed into engagement with a spur gear loosely rotating on the driven shaft. Thereby the rotary movement of the driving pinion is transmitted to the selected driven shaft for such a time until the coupling remains in engagement via the adjusting lever and the adjusting shoe with the threaded spindle. During displacement of the threaded spindle, a spring presses the connected coupling out of engagement and another driven shaft can be connected in the same manner.
The distributing transmission having the mechanical adjusting elements is advantageous as compared with the electromagnetically adjustable distributing transmission, in the sense of the space consumption and economicalm manufacture suitable for mass production, and also in the sense of weight economy. However, the space consumption required for the mechanically adjustable distributing transmission and the number of structural elements are relatively high, so that the manufacturing costs for a mechanically actuated distributing transmission are considerable.